Originally Posted by
CCayley
I read your comment, but though your question is right, the conclusion is wrong. If you look at HMRC guidance on employees claiming deductions they say it is for amounts that 'must' be incurred. So if someone has to get to New York to see a client but the employer won't pay for a ticket the employee can deduct the ticket cost, and you are right that it would not matter whether the employee could have got a cheaper ticket in a lower class of travel or on another airline. But in OP's case the employer provides a ticket that OP chooses to upgrade. This isn't something that OP 'must' do so it isn't deductible.
Sounds like twisted logic to me. The guidance is dealing with the issue of what class of travel can be re-imbursed. It does not deal with whether it can be an upgrade or not an upgrade, or whether an upgrade is only allowable if paid for by the employer.
Further, nothing in that guidance that I understand refer to "must" being incurred or expenditure being limited to circumstances where the employer does not provide the ticket. It deals with "wholly, necessarily and exclusively" being the test and the guidance would seem clear that First class travel (however paid for) meets that test.
What the guidance on this point is concerned with is whether the
journey or expenditure is necessary not who paid for it! There are some parts of the guidance which depend upon who paid for the expenditure but this is not it.